1. Field of the Invention
The present invention relates generally to improvements to systems and methods for winding optical fiber onto spool, and more particularly to advantageous aspects of a system and methods for controlling turnaround positions at spool flanges.
2. Description of the Prior Art
In typical prior art winding machines, optical fiber is wound onto the barrel of a rotating spool up and down its length between a pair of spool flanges. The control of the winding process has been a challenge for many years. One issue that has been particularly challenging is the control of the turnaround positions, i.e., the point at each flange at which the transverse motion of the spool relative to the fiber is reversed.
A turnaround should ideally occur at the point where the fiber has just reached a flange. Turnaround positions are therefore commonly preset based upon a standard size takeup spool, with flanges of known thickness. However, because of variability in spool manufacture, the turnaround position may not be precisely correct for a particular flange. If the turnaround occurs too late, an excess of fiber may accumulate at the flange, resulting in what is called a xe2x80x9cdogbonexe2x80x9d condition. If the turnaround occurs too early, a gap may result at the flange. Another condition that may arise if the turnaround occurs too early is a xe2x80x9ccascadexe2x80x9d condition, in which the fiber is wound onto the spool in a non-uniform, serpentine curl. Any of these conditions will cause fiber to be wound unevenly at the flange. These error conditions are particularly significant in the manufacture of optical fiber, where an improper winding of the spool may have a detrimental effect on fiber performance.
Prior art systems typically provide only for manual intervention by an operator to control the turnaround points of the spool based upon an observed dogbone or flange gap condition. However, this approach is disadvantageous for a number of reasons. First, it requires a number of turnarounds for a dogbone or flange gap condition to become apparent to an operator. Second, adjustment of the turnaround position is imprecise and requires several additional turnarounds to confirm that the error condition has been in fact corrected. These factors greatly decrease the efficiency of the winding process.
There is thus a need for an automatic system for adjusting the turnaround position at spool flanges in a winding machine.
A presently preferred embodiment of the invention provides a system for winding optical fiber onto a spool. The system comprises a spindle assembly for receiving the spool and rotating it around its longitudinal axis. A fiber source for providing a continuous supply of fiber to the spool is positioned relative to the spindle assembly such that rotation of the spool by the spindle assembly causes fiber to be wound onto the spool around its longitudinal axis. A tension sensing device senses and provides feedback related to the amount of tension in the fiber being wound onto the spool. A traverse means causes the fiber to wind onto the spool back and forth between a front spool flange and a rear spool flange, the traverse means including a front turnaround position at the front spool flange and a rear turnaround position at the rear spool flange. A controller receives the fiber tension feedback and uses the feedback to determine what adjustment, if any, is to be made to the front and rear turnaround positions.
Additional features and advantages of the present invention will become apparent by reference to the following detailed description and accompanying drawings.